If you think spending 350$ on a tv is cheap than i dont know what you're thinking

Whenever i just select 720p and i launch GTA 5 my screen goes blue and says no signal .. but yet i can play the last of us in 1080p doesnt make sense

How do i force 720p?

When i launch GTA 5 my game runs in 480p SD it says also im on the ps3 if that helps i can run other games in 1080p it says. I dont know much about this kinda stuff some help would be nice. This is the TV i have. http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6764194. If you need me to answer any other questions about the tv or the game just ask all feedback / help is needed! Thank you have a nice day.